Back thinking about going through and building a car and am once again looking around for an engine. My question is how would I know if the explorer 5.0 has the gt40 or gt40P heads? If I'm buying an engine off of Ebay or finding one at my local junkyard how can I tell the difference? Also, from what I remember from the last time I installed a manual transmission the crankshaft is machined differently than one that is using an auto trans. I thought the MT crank had a hole drilled in the end. It has been years, am I correct? Do all of the 5.0's have a crankshaft that will accept a manual trans?

 

Welcome to the party!! Disclaimer this is cut and pasted from a former Jason post I know nearly nothing myself about this:


The Explorer motor may get you an awesome set of heads and a good intake or it may not. Early 5.0 Explorers had "GT40" heads and intakes, later ones had "GT40P" heads and intakes. The GT40 intake has provisions for EGR while the P does not. If you do not need to run emissions ether will work for you. The GT40 heads have the same spark plug angle as Mustang E6 heads, which is what the Monster Miata kit's headers are designed around. The GT40P's have a differnt angle which will not work with the kit's headers.

To tell the difference:

Heads-GT40's have three vertical bars cast into them at the front and back. GT40p's have 4. GT40 plugs come out at an angle, GT40P's come stright out.

Intake-GT40P's will have a gap in the lower intake between the first four runers and the last four. GT40's will be cast across that and have a small 3/4 or so inch hole in that spot that leads to the exhaust chambers on the heads.

In ether case you'll get a nice 65mm throttle and some nice later-model 19 pound injectors that can be used. If you want EGR you'll need to buy a 65mm Mustang EGR spacer to go between the intake and throttle. If you're not doing EGR you can bolt the throttle directly to the intake.

The Explorer front accessories are not the same as a Mustang. If you don't need AC or PS you can go with the Explorer stuff and gain a little room beween the engine and radiator. If you do want ether of those you'll have to source the Mustang stuff. All of it can be found on eBay used or through Ford racing new.

The Explorer has a cast aluminum oil pan. Monster Miata will need a steel Msutang one to modify. Since most used pans are pretty bad at this point any how this is pretty much a non issue. I always just have a new pan drop shipped to him. You will need to source a Mustang oil pick up and new Mustang oil pump. Again, the pump is a non-issue as you should be putting a new one in anyhow.

The Explorer runs a distributorless ignition system. You'll need to pick up a Mustang duistributor. They are $120 at Autozone. Get one with the TFI module included and then relocate it using one of my kits.

In the same post Jason had some transmission comments.

The 1983 T5 will be a non-WC T5 (non World Class). These transmissions are different from the later WC transmissions in that they have bronze sycros as opposed to the later teflon ones and the input shaft sleeve (the part the throwout rubs on) will be cast as opposed to steel. The only differnce you may feel from your end is a bit harder shifting due to the sycros. The shaft sleeve can be easily replaced with a later steel one which I would do if you see any damage to it. They are pretty cheap.
It's claimed that they are not rated for the same torque as a WC trans. I actually used one for my first and second builds and had no problems with them. As an added bonus, the rebuild kits are about $100 cheaper than the WC rebuild kits. $150 for a trans, bell and shifter is good. A new bell alone is $200.

Make sure you get a block plate if it does not come with the trans. The Explorer one will not work. A guy o eBay makes new ones from aluminum for a very reasonable price. Go that route before OEM or used.

Good luck and don't be a afraid to dig around in old threads here. Tons of good stuff!